PROK2 and neoplasm: Gr‐1+CD11b+ cells also promoted tumor angiogenesis through the G‐CSF/STAT3/prokineticin 2 (Bv8) axis, while anti‐BV8 treatment could significantly reduce the tumor volume and decrease the number of Gr‐1+CD11b cells and their activity, indicating the positive role of MDSCs in tumor angiogenesis [134, 135].